You can find this option on the "Top Section" tab within "Project | Website Options". The Website feature in Fast-Help creates a three pane website, with a Top Section, a Contents section on the left and the Help Text section on the right. The screen-shot is described in detail below:-
This is how tall the Top Section will be in pixels. If you have a large image or lots of text you will need to adjust this. Please note that you will also need to adjust the position of the three navigation images. You can do this from the "Position from Top" field in the Images section of the "Contents" tab.
Use the drop down arrow to select a color for the background of the Top Section.
Use the [...] ellipsis button to select an image that will be used to tile the background of your Top Section.
Show Contents Tab
If this option is checked then the image specified will be used to display the Contents. Please ensure this image, and the Index and Search images, are kept in the "..\Templates\Website\Images" folder, off your Installation folder.
Show Index Tab
If this option is checked then the image specified will be used to display the Index tab.
Show Search Tab
If this option is checked then the image specified will be used to display the Search tab.
Hints for the Tabs
When you compile your Website Help and pass your mouse over the Contents, Index and Search tabs you will see a hint showing the name of each tab. You can customize these hints by using Reserved Variables. Click here to find out more.